The number of computers in business and private applications is growing at an enormous rate and many firms have thousands of computers throughout their organizations. In contrast to the high security traditionally afforded computer equipment in the past, the portable, desktop and deskside are not generally located in high security areas or, as in the past, operated by a few highly trained and highly trusted personnel. Currently, personal computers are often left on desks where anyone with an operating system boot diskette can access any data stored within the computer with the potential for theft and/or tampering of proprietary information. Additionally, the location of such computers in unsecured areas and their relatively small physical size leads to the theft of the equipment itself. When a computer system is stolen so is the valuable information contained within it.
Thus, the data stored in either a portable, desktop or deskside computer is highly vulnerable to unauthorized access merely because these computers are relatively easy to remove from the owner's premises. This data is contained in system memory and nonvolatile secondary storage such as floppy disks, hard disks, tape, magneto-optical writable media, etc. And while information contained in the volatile system memory of AC-powered desktop or deskside computers will very likely be lost as a direct result of physically removing the computer, a portable battery operated computer can hold the contents of memory for several hours. In addition, if the computer is equipped with rapid resume capabilities, system software has the ability to copy the contents of volatile system memory onto nonvolatile secondary storage making the record of the information previously contained in system memory permanent. Thus, once the system unit, along with its internal storage devices and media are removed from the owner's premises, the data intrusion expert has unlimited time and tools available to mine the sensitive information contained within.
The traditional prior art approach to protecting the data contained in a computer system is to wrap the storage device in a steel case and provide lockable doors to prevent the removal of removable media such as floppy disks. The unit is then affixed to something considered to be immovable such as a column, desk or large table. Often the means of affixing the system unit is a steel cable. Obviously, none of these crude measures are effective against a determined and clever thief.
As an example, assume that a computer system is provided with a lockable cover and the covers and locking mechanism are designed so as to make any attempt at unauthorized entry evident. Even if the cover and lock arrangement works and produces clear evidence that the covers have been tampered with, once the computer system is removed from the owner's premises, the evidence is removed as well.
Another security feature often provided is the entry and verification of a password before allowing access to any data contained in the computer. This is only effective as long as the storage devices remain secured within a locked and intact enclosure. Once the physical defenses of the system unit are breached, the thief is free to attach the storage device to another computer which he can use as a tool to access the data contained therein.